Folks who're annoyed about the inability to move to another instance without being able to take your followers with you:
"Account migration" has been a feature request on the Github issue list for quite a long time. https://github.com/tootsuite/mastodon/issues/177
It is a BIG job, but it is on the list and the devs are aware of it. It could take a long time.
Clicking through to the issue on Github and clicking "thumbs-up" and leaving a comment about your suboptimal new-user experience is really helpful.
The original server operated by the Mastodon gGmbH non-profit